Endogenous hydrogen sulfide inhibition suppresses tumor growth by promoting apoptosis and pyroptosis in esophageal cancer cells.

BACKGROUND: Hydrogen sulfide (H2S) has been identified as the third gaseous signaling molecule. Endogenous H2S plays a key role in the progression of various types of cancer. However, the effect of endogenous H2S on the growth of esophageal cancer (EC) remains unknown. METHODS: In this study, three kinds of H2S-producing enzymes inhibitors, DL-propargylglycine (PAG, inhibitor of cystathionine-γ-lyase), aminooxyacetic acid (AOAA, inhibitor of cystathionine-ß-synthase), and L-aspartic acid (L-Asp, inhibitor of 3-mercaptopyruvate sulfurtransferase) were used to determine the role of endogenous H2S in the growth of EC9706 and K450 human EC cells. RESULTS: The results indicated that the combination (PAG+AOAA+L-Asp) group showed higher inhibitory effects on the viability, proliferation, migration, and invasion of EC cells than PAG, AOAA, and L-Asp group. Inhibition of endogenous H2S promoted apoptosis via activation of mitogen-activated protein kinase pathway in EC cells. Endogenous H2S suppression triggered pyroptosis of EC cells by activating reactive oxygen species-mediated nuclear factor-κB signaling pathway. In addition, the combine group showed its more powerful growth-inhibitory effect on the growth of human EC xenograft tumors in nude mice without obvious toxicity. CONCLUSION: Our results indicate that inhibition of endogenous H2S production can significantly inhibit human EC cell growth via promotion of apoptosis and pyroptosis. Endogenous H2S may be a promising therapeutic target in EC cells. Novel inhibitors for H2S-producing enzymes can be designed and developed for EC treatment.

Synthesis of calcium carbonate-quince bio-composite for programmed and on-demand drug release of paracetamol at target site: a green chemistry approach.

In this study, an inorganic-organic composite system was developed through biomineralization of calcium carbonate in the quince-seed mucilage-based hydrogel. Drug-polymer interactions were studied by FTIR, DSC, XRD and SEM analysis. The water absorption capacity was calculated by swelling index. Drug release was determined at various pH. Several in vitro kinetic models were applied to observe drug release behaviour. Studies of drug-polymer interactions and particle flow characteristics of the developed composite material have shown that there is good compatibility between drug and the excipients. The XRD and SEM results confirmed calcite polymorphs in the developed composite material. Thermograms showed that the developed composite material was heat stable. A restricted drug release was observed in an acidic medium (pH 1.2). A controlled drug release was depicted from the developed system at pH 6.8. The drug release mechanism of Super Case II was suggested. The developed system was considered to be an effective drug carrier for colon targeted oral delivery of non-steroidal anti-inflammatory drugs (NSAIDs) to avoid gastric irritation and risk of ulceration. Graphical abstract: An illustration of extraction of quince hydrogel and development of calcium carbonate-quince (CaCO3-Q) composite system; QSM = Quince seed mucilage. Supplementary Information: The online version contains supplementary material available at 10.1007/s00289-022-04400-1.

The Role of Hydrogen Sulfide in Respiratory Diseases.

Respiratory diseases are leading causes of death and disability around the globe, with a diverse range of health problems. Treatment of respiratory diseases and infections has been verified to be thought-provoking because of the increasing incidence and mortality rate. Hydrogen sulfide (H2S) is one of the recognized gaseous transmitters involved in an extensive range of cellular functions, and physiological and pathological processes in a variety of diseases, including respiratory diseases. Recently, the therapeutic potential of H2S for respiratory diseases has been widely investigated. H2S plays a vital therapeutic role in obstructive respiratory disease, pulmonary fibrosis, emphysema, pancreatic inflammatory/respiratory lung injury, pulmonary inflammation, bronchial asthma and bronchiectasis. Although the therapeutic role of H2S has been extensively studied in various respiratory diseases, a concrete literature review will have an extraordinary impact on future therapeutics. This review provides a comprehensive overview of the effective role of H2S in respiratory diseases. Besides, we also summarized H2S production in the lung and its metabolism processes in respiratory diseases.

Role of hydrogen sulfide donors in cancer development and progression.

In recent years, a vast number of potential cancer therapeutic targets have emerged. However, developing efficient and effective drugs for the targets is of major concern. Hydrogen sulfide (H2S), one of the three known gasotransmitters, is involved in the regulation of various cellular activities such as autophagy, apoptosis, migration, and proliferation. Low production of H2S has been identified in numerous cancer types. Treating cancer cells with H2S donors is the common experimental technique used to improve H2S levels; however, the outcome depends on the concentration/dose, time, cell type, and sometimes the drug used. Both natural and synthesized donors are available for this purpose, although their effects vary independently ranging from strong cancer suppressors to promoters. Nonetheless, numerous signaling pathways have been reported to be altered following the treatments with H2S donors which suggest their potential in cancer treatment. This review will analyze the potential of H2S donors in cancer therapy by summarizing key cellular processes and mechanisms involved.

Multifaceted behavior of PEST sequence enriched nuclear proteins in cancer biology and role in gene therapy.

The amino acid sequence enriched with proline (P), glutamic acid (E), serine (S), and threonine (T) (PEST) is a signal-transducing agent providing unique features to its substrate nuclear proteins (PEST-NPs). The PEST motif is responsible for particular posttranslational modifications (PTMs). These PTMs impart distinct properties to PEST-NPs that are responsible for their activation/inhibition, intracellular localization, and stability/degradation. PEST-NPs participate in cancer metabolism, immunity, and protein transcription as oncogenes or as tumor suppressors. Gene-based therapeutics are getting the attention of researchers because of their cell specificity. PEST-NPs are good targets to explore as cancer therapeutics. Insights into PTMs of PEST-NPs demonstrate that these proteins not only interact with each other but also recruit other proteins to/from their active site to promote/inhibit tumors. Thus, the role of PEST-NPs in cancer biology is multivariate. It is hard to obtain therapeutic objectives with single gene therapy. An especially designed combination gene therapy might be a promising strategy in cancer treatment. This review highlights the multifaceted behavior of PEST-NPs in cancer biology. We have summarized a number of studies to address the influence of structure and PEST-mediated PTMs on activation, localization, stability, and protein-protein interactions of PEST-NPs. We also recommend researchers to adopt a pragmatic approach in gene-based cancer therapy.

Roles of Hydrogen Sulfide Donors in Common Kidney Diseases.

Hydrogen sulfide (H2S) plays a key role in the regulation of physiological processes in mammals. The decline in H2S level has been reported in numerous renal disorders. In animal models of renal disorders, treatment with H2S donors could restore H2S levels and improve renal functions. H2S donors suppress renal dysfunction by regulating autophagy, apoptosis, oxidative stress, and inflammation through multiple signaling pathways, such as TRL4/NLRP3, AMP-activated protein kinase/mammalian target of rapamycin, transforming growth factor-ß1/Smad3, extracellular signal-regulated protein kinases 1/2, mitogen-activated protein kinase, and nuclear factor kappa B. In this review, we summarize recent developments in the effects of H2S donors on the treatment of common renal diseases, including acute/chronic kidney disease, renal fibrosis, unilateral ureteral obstruction, glomerulosclerosis, diabetic nephropathy, hyperhomocysteinemia, drug-induced nephrotoxicity, metal-induced nephrotoxicity, and urolithiasis. Novel H2S donors can be designed and applied in the treatment of common renal diseases.

Taking a holistic view of PEST-containing nuclear protein (PCNP) in cancer biology.

Polypeptide sequences enriched with proline (P), glutamic acid (E), aspartic acid (D) and serine (S)/ threonine (T) (PEST) have been reported to be the most abundant and frequently distributed at the cellular level. There is growing evidence that PEST sequences act as proteolytic recognition signals for degradation of residual proteins which is critical for activation or deactivation of regulatory proteins involved in cellular signaling pathways of cell growth, differentiation, stress responses and physiological death. A PEST containing nuclear protein (PCNP) was demonstrated as a tumor suppressor in a neuroblastoma cancer model and tumor promoter in lung adenocarcinoma cancer model. Its unique properties like ubiquitination by NIRF, co-localization with NIRF in nucleus and tumor progression attract the attention of researchers. PCNP was reported to be ubiquitinated by ring finger protein NIRF in E3 ligase manner and as modulator of MAPK and PI3K/AKT/mTOR signaling pathways. In this review, we summarize PCNP linked DNA damage response, Post translational modifications, and transportation to address initiation, prognosis, and resistance of tumor cells in terms of cell cycle regulation, transcription and apoptosis. Hence, we demonstrate PCNP as a novel target in cancer diagnosis and treatment.

Gelatin-based hydrogels as potential biomaterials for colonic delivery of oxaliplatin.

In present investigation, gelatin-based (AA-co-AMPS) hydrogels were prepared using N, N'-Methylenebisacrylamide (MBA) as a cross-linker and ammonium per sulfate (APS) as an initiator. The successful crosslinking and network formation was confirmed by Fourier transform infrared spectroscopy (FT IR). Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) investigations proved the higher thermal stability and successful entrapment of oxaliplatin (OXP) in the polymeric network. X-ray diffraction (XRD) confirmed the loss in crystallinity of the drug after loading in the hydrogel. Scanning electron microscopy (SEM) revealed the porous surface of the hydrogel. The newly formed hydrogels were responsive to change in pH. The swelling, drug loading and drug release was increased with increase in concentration of acrylic acid (AA) while gelatin and 2-acrylamido 2-methylpronesulfonic acid (AMPS) were found to act inversely. The in-vitro enzymatic degradation study showed that the blank hydrogels were more stable against the blank PBS than the collagenase and lysozyme. MTT-assay proved that the blank hydrogels were cyto-compatible while free OXP as well as OXP-loaded hydrogels showed dose dependent controlled cytotoxicity against Vero, MCF-7 and HCT-116 cell lines. The preliminary safety evaluation and oral tolerability showed that the hydrogel suspension was biocompatible and well tolerable upto 4000 mg/kg of body weight without causing any hematological or histopathological changes in rabbits.

Development of Dual Drug Loaded Nanosized Liposomal Formulation by A Reengineered Ethanolic Injection Method and Its Pre-Clinical Pharmacokinetic Studies.

Oleanolic acid (OA), which is a natural pentacyclic terpenoid, has been identified for hepato-protective, nephron-protective and cardio-tonic properties. In contrast, doxorubicin (DOX) is a famous anti-cancer drug but its efficacy is a question mark because of its known cardio-toxicity. We developed a combined nanoliposomal formulation of DOX with OA, as adjuvant, to overwhelm toxic effects of DOX without compromising anticancer activity. The entrapment efficiency and the particle size were brought in limit by the reengineered ethanolic injection method (REIM), without further extrusion. The developed formulations were stable over the study period of two months. A modified HPLC method was employed for the analysis of OA (drug retention time, Tr = 12 ± 1 min). The recovery of OA against spiked plasma samples was more than 90%. MTT assay showed anti-apoptotic synergism against HepG2 cells at non-fixed ratio (combination index, CI < 1). A sustained in vivo drug release of experimental drugs was depicted over 24 h. Histopathological examination and laboratory findings indicated no visible sign of toxicity in the treated mice group against combined delivery. Hence, this combined nanoliposomal formulation was tagged as a safer therapy for the DOX based cancer treatments.

Liposomal co-delivered oleanolic acid attenuates doxorubicin-induced multi-organ toxicity in hepatocellular carcinoma.

Doxorubicin in combination with other cytotoxic drugs has clinical advantages. However, doxorubicin-induced cardiotoxicity negatively impacts clinical utility and outcomes. Cardiotoxicity can result from increased oxidative stress or from a local cytochrome P450 mediated increase in 20-hydroxy-5, 8, 11, 14-eicosatetraenoic acid (20-HETE). Oleanolic acid (OA) is a natural pentacyclic triterpenoid with free radical scavenging, cardioprotective, and P450-mediated cyclooxygenase-upregulating properties. We investigated co-delivery of liposomal OA and doxorubicin in a HepG2 model of hepatocellular carcinoma (HCC). OA attenuated the cardiotoxicity induced by doxorubicin without compromising its anticancer activity. Apoptosis assays revealed that co-delivery of DOX and OA produced a synergistic anticancer effect. However, the drugs had antagonistic effects on cardiomyocytes. Female BALB/c nude mice treated with OA- and DOX-loaded liposomes (ODLs) exhibited reduced tumor growth, stable body weight, and stable organ indices. Reduced 20-HETE production suggested ODLs had limited cardiotoxicity. No changes in biochemical or histopathological markers were observed in mice treated with ODLs. Tailored co-delivery of OA and DOX may thus be an effective therapeutic strategy for treating HCC.

Integrated scientific data bases review on asulacrine and associated toxicity.

Asulacrine (ASL), a weakly basic and highly lipophilic drug was synthesized in 1980's in cancer research laboratory of Auckland by modifications to the acridine portion of amsacrine on 3-, 4- and 5-substitution patterns. In contrast to its precursor amsacrine (m-AMSA), ASL was effective not only against leukemia and Lewis lung tumor system but also a wide variety of solid tumor. Its metabolic pathway is not same to amsacrine hence different side effects, hepatotoxicity and excretion was observed. Asulacrine is under phase II clinical trials and has showed promising results but its toxicity especially phlebitis is stumbling block in its clinical implementation. This review is an effort to give a possible clue, based on scientifically proven results, to the researchers to solve the mystery of associated toxicity, phlebitis. Review covers the available literature on asulacrine and other acridine derivatives regarding pharmacology, pharmacokinetics, quantitative structure activity relationship and toxicology via electronic search using scientific databases like PubMed and others. To date, all abstracts and full-text articles were discussed and analyzed. The tabulated comparisons and circuitry mechanism of ASL are the added features of the review which give a complete understanding of hidden aspects of possible route cause of associated toxicity, the phlebitis.

Identification and characterization of in vivo metabolites of asulacrine using advanced mass spectrophotometry technique in combination with improved data mining strategy.

Asulacrine (ASL) is a broad-spectrum, antitumor drug whose data are promising for the treatment of breast and lung cancers; however, a high incidence of phlebitis hampered its further development. Phlebitis is associated with generation of reactive species. Asulacrine donates electrons and produces oxidative stress in chemical reactions. It was expected that ASL would actively metabolize to oxidized products through reactive intermediates and produce more products in vivo than reported and thus cause phlebitis. A comprehensive study was planned to investigate in vivo metabolism of ASL, using high-resolution mass spectrometry LC/IT-TOF MS in positive mode. Metabolites were detected by different software by applying annotated detection strategy. The possible metabolites and their product ions were simultaneously detected by segmented data acquisition to get accurate mass values. Segmented data acquisition improved signal-to-noise (S/N) ratio, which was helpful to detect metabolites and their fragments even when present in trace amounts. A total of 21 metabolites were detected in gender-based biological fluids and characterized by comparing their accurate mass values, fragmentation patterns, and relative retention times with that of ASL. Among previously reported glucuronosylation metabolites, some oxidation, hydroxylation, carboxylation, demethylation, hydrogenation, glutamination, and acetylcysteine conjugation were detected for the first time. Twenty metabolites were tentatively identified by using the annotated strategy for data acquisition and post-data mining.

RATIONALIZED AND COMPLEMENTARY FINDINGS OF SILYMARIN (MILK THISTLE) IN PAKISTANI HEALTHY VOLUNTEERS.

The aim of the work was to examine the influence of gender on pharmacokinetics of silymarin; a basic constituent of medicinal herb "milk thistle" (Silybum marianum). The presented work is the extension of published work of Usman et al. (16). The comparative parallel design pharmacokinetic study was conducted in Pakistani healthy volunteers (male and female) receiving a single 200 mg oral dose of silymarin. Sixteen subjects (8 males and 8 females) were enrolled and completed the 12 h study. Blood screening was done on HPLC and the pharmacokinetic parameters were calculated by APO, 3.2 Ver. software using non-compartmental and two compartment model approaches. A significant difference (p < 0.05) was observed in almost all calculated pharmacokinetic parameters of silymarin in male and female. Clinically, the silymarin has been underestimated in the previous study. Gender based clinical investigations should be directed in the future on other flavono-lignans of 'milk thistle' as well.